Electric wall switch



April 17, 1962 M. EHRLICH ETAL.

ELECTRIC WALL SWITCH 5 Sheets-Sheet 1 Filed June 5, 1958 H mv www www um IWW X C a B 5 Sheets-Sheet 2 Filed June 5, 1958 April 17, 1962 M. EHRLICH ETAL ELECTRIC WALL SWITCH 5 Sheets-Sheet 5' Filed June 5, 1958 United States Patent Oliice 3,036,479 Patented Apr. 17, 1962 3,030,479 ELECTRIQ WALL SWITCH Maximilian Ehrlich, Baldwin, and `lean Polialr, New York, NX., assignors to Leviton Manufacturing Co., Inc., Brooklyn, NSY., a corporation of New York Filed .lune 5, 1958, Ser. No. 740,@30 17 Claims. (Cl. 20G- 168) This invention relates to an electric wall switch and relates, more particularly, to an electric wall switch of the quiet-operating type yfor use with alternating current.

An object of the present invention is to provide an electric wall switch of the quiet-operating type which can be manufactured at lowcost and which is eliicient and durable in operation. Another object of the invention is to provide an electric switch of the quiet-operating type which is compact and can be readily interchanged with or substituted for existing electric wall switches. A further object of the invention is to provide an electric wall switch of the quiet-operating type which incorporates wiring terminals which do not require the use of screws or the like in the making of electrical connections to the switch.

Various other objects and advantages of the invention will be apparent and best understood from the following description and the accompanying drawings in which:

FIG. 1 is a side View in vertical section taken along the line il--l of FIG. 3 of an electric wall switch embodying the invention;

FIG. 2 is a side view in vertical section taken along the line 2 2 of FIG. 3 of the switch shown in FIG. l;

FIG. 3 is a top plan view of an electric switch embodying the present invention, with certain parts removed for clarity;

FIG. 4 is a side view of certain operating parts of the switch shown in FIGS. 1 3;

FIG. 5 is a plan view of a Contact supporting member forming part of the switch shown in FIGS. 1-3;

FIG. 6 is an end view of the contact supporting member shown in FIG. 5;

FIG. 7 is a section view taken along line 7--7 of FIG. 5;

FIG. 8 is a section view taken along line 8-8 of FIG. 5;

FIG. 9 is a perspective view of a wiring terminal forming part of the switch shown in FIGS. 1-3, but on an enlarged scale;

FIG. l0 is a section view taken along line 10-10 of FIG. 9;

FIG. 1l is an exploded view in perspective of contact elements for the switch shown in FIGS. l3, but on an enlarged scale; and

FIG. l2 is a perspective view of an operating lever forming part of the switch shown in FIG. l, but on an an enlarged scale.

Referring to the drawings in detail, there is a hollow housing 10 of rectangular shape which may be molded from a suitable insulating material.

The housing it) is open at its top and has three wirereceiving openings or apertures 11 which extend through the bottom thereof. Two of the wire-receiving openings are spaced apart at one end of the bottom of the housing and the other wire-receiving opening is located at the other end of the bottom of the housing. The wire-receiving openings permit the bared ends of electric wires to be inserted therethrough into the matter of the housing in making electrical wiring connections to the switch. In addition, openings or apertures 12 which permit the insertion of a releasing tool (not shown) into the interior of the housing are formed in the bottom of the housing adjacent each of the wire-receiving openings.

The end walls of the housing have vertically extending slots or grooves 13, 14, and 15- which are shaped to receive vertical portions of contact elements 16, 17, and 1S, respectively, formed in the interior surfaces thereof. The contact-receiving grooves are positioned so that the lower end of each groove terminates adjacent one of the wire-receiving openings in the bottom of the housing.

`A contact retaining or positioning block 19 of insulating material which is fitted within the housing, engages with and holds the respective contact elements in the grooves in end walls of the housing. The block may be secured in place by a Arivet 2l) and it has triangularly shaped recesses or channels 21, 22, and 23 formed therein opposite the contact-receiving grooves 13, 14, and 15, respectively. Each of the recesses has an opening facing one of the contact elements located in the grooves in the end walls of the housing and an opening facing the set of wire and tool receiving openings associated therewith. The openings facing the `contact elements are narrower than the portion of the contact elements located in the grooves and hence, the retainingy block holds the Contact elements in place.

As shown best in FIGS. l and 2, a wire-engaging member 24 of a resilient material, such as spring steel, is locatedv in each of the triangularly shaped recesses in the retaining block. The wire-engaging members are L- shaped and each has an anchoring arm 25 which extends upwardly into a centrally located opening 26 or 27 on one side of the block and a resilient wire-engaging arm 28 which extends' across the triangular shaped recess in which it is mounted. The ends of the spring arms extend over the wire-receiving openings in the bottom of the housing and oppose the terminal portion of the contact elements located in the respective contact-receiving slots in the end walls of the housing. The ends of the resilient wire-engaging arms have sharp inclined edges 29 which bite into the bare end of a conductor wire inserted between the end of the arm and the terminal portion of the contact element. As shown best in FIGS. 1 and 11, the' contact elemen 16 is U-shaped and the legs of the U extend along the top and bottom of the retaining block. An upwardly facing contact button 30 is carried by the leg of the U on top of the retaining block. The bottom 16a of the U which extends vertically, forms a terminal portion and iits into the slot 13 in the end wall of the housing (at the left in FIGS. 1 and 3). The leg 16b of the U which iits into a recess 19a in the bottom of the block, has an elongated opening 16e formed therein which overlies the associated wire-receiving opening in the bottom of the housing.

As shown ybest in FIGS. 2 and ll, the contact element 17 is L-shaped and has a vertical leg 17a which lits into the slot 14 in the end wall of the housing (at the left in FIGS. 2 and 3). 'Ille vertical leg 17a forms a terminal portion and an offset arm 171: formed at the top thereof extends forwardly across the housing to a point above the contact button on the leg of the U-shaped contact element on top of the retaining block. The offset arm carries a downwardly facing contact button 3.1 which is positioned in opposing spaced relation to the upwardly facing contact button on the U-shaped contact element. An inwardly extending tab 17C Struck from the vertical leg rests on top of the block and insures proper vertical spacing of the contact elements.

The contact elements 16 and 17 are, thus, held in xed positions at one end of the housing. The other Contact element 18 has a vertical leg or anchoring member 18a which ts into the contact receiving slot at the other end wall of the housing and forms a terminal portion (see FIGS. l and 11). A spring arm 13b extends from the sesame top of the vertical leg lengthwise across the housing to a point where the end of the arm is between the opposing portions of the two xed contact elements. The spring arm carries contact buttons 33 at its end in opposing relation to the contact buttons on the fixed contact elements and which can be moved into and out of engagement therewith by movement of the spring arm. The spring arm is normally biased so that the contact button on top thereof is in engagement with the downwardly facing button carried by the L-shaped contact element at the top of the housing, as shown in PEG. 1.

Each of the contact elements may be formed from a strip of electrically conductive metal such as copper, and the contact buttons carried thereon may be formed of silver or other suitable conducting material. As de-V scribed above, the contact elements and the wire-engaging members are held in their respective positions in the housing by the retaining block or insert and they may be assembled in the housing without diiculty. The switch illustrated and described has two fixed contacts and a movable contact so that it will function as a three-way switch. However, it will be understood that one of the fixed contacts may be omitted from the structure if a two pole switch is desired.

A cover 34 of insulating material closes the opening in the top of the housing 16 and has a slot 3S formed therein through which the end of an operating lever Se of insulating material extends. The operating lever has trunnions 37 extending from its sides with bearing surfaces 258 formed thereon resting in semicircular recesses- 39 (FlG. 3) formed in the tops of the. sidewalls of the housing 11) md with bearing surfaces e@ formed thereon engaging with recesses 41 formed in the housing cover (see FIG. 2). Thus, they operating lever is pivotally mounted in the housing for arcuate movement in the slot in the cover between extreme positions at the ends thereof.

A Contact actuating: cam 42 carried by Vthe operating lever 36 at one side thereof engages with and depresses they movable spring arm 18h of the contact element 18 in movement of the operating lever in one direction (from right to left as shown in FIG. 1) and brings it into engagement with the lower fixed contact element as shown in FIG. 4. Movement of the operating lever in the opposite direction permits the spring arm to rise and return to its normal position in engagement with the upper xed contact element as shown in FIG.' 1.

The retainingblock i9 in the housing has a channel 43 formed in its upper surface (see PEG. 8). The channel is located in the. center of one block and extends lengthwise thereof. A U-shaped lever positioning spring 44 is tted into the channel. The spring d4 is formed from a doubled length of flat stock and the upper arm 45 thereof extends lengthwise across the top of the housing beneath the operating lever. The upper arm of the spring has cam surfaces 46 and 47 formed thereon which engage with acam member 43 carried by the lever as the lever is moved from one extreme position to the other extreme position thereof. The cam surfaces 46 and 47 are so formed that they impart a snap action to the operating lever and urge the lever in one direction or the other, depending on which of the surfaces is in engagement with the cam member. Tue lever positioning spring is arranged to exert the same force on the lever in movement of the lever in either direction. The force exerted by the positioning spring is much greater than the force exerted by the spring arm of the movable contact and hence, the effect of the spring arm on the lever is of little consequence in movement of the operating lever.

To cushion the action of the operating lever at its eX- treme positions, a resilient member 49 of soft rubber or other compressible material, is mounted on top of the retaining block and is held in position by legs t? which extend into openings 51 and 51a in the top of the block (see FIG. 2). The opening 51a extends through the block and accommodates the rivet 2i). Stops 52 formed on the operating lever strike the top of cushion 49 and arrest the travel of the operating lever without undue noise in movement of the operating lever in either direction.

The cover is attached to the housing in the usual manner by means of a clamping plate 53 which extends over the top of the cover and has legs which t into grooves in the side of the housing. Attachment of the cover to the housing holds the operating lever andthe elements associated therewith in assembled relation without screws or the likeln connecting the switch to an electrical wiring circuit, the end of a conductor wire A is stripped of insulation and is then inserted through one of the wire-receiving openings il in the bottom of the housing. The end of the wire as it enters the housing contacts with the terminal portion of one of the contact elements which is shaped to guide the wire and with the end of the spring arm of the wire-engaging member opposing the contact. Insertion of the wire raises the end of the spring arm until the wire can pass between the end thereof and the opposing terminal portion of the Contact element, as shown for example in FlGS. l and 9. When this occurs, the spring arm of the wire-engaging member forces the bare wire against and into Contact with the opposing terminal portion and establishes good electrical connection between the wire and the contact element. Pulling on the wire causes the sharp edge Z9 at the end of the spring arm to bite into the wire and resist removal of the wire by jamming the wire more tightly against the terminal portion of the contact element. Withdrawal of thev wire may be accomplished easily by inserting the end of a screwdriver or the like through the releasing tool aperture and raising the end of the wire-engaging member from the engagement with the wire.

It will be understood that various modifications and changes may be made in the embodiment of the invention described and illustrated herein without departing from the scope of the invention as defined by the claimsl appended hereto.

We claim:

1. In an electrical wall switch, the combination comprising a hollow housing, said housing, having a bottom and side and end walls extending upwardly therefrom, said bottom having spaced wire-receiving openings formed therein at points adjacent the inner surfaces of the end walls of the housing, a pair of contact elements mounted within the housing at opposite ends thereof, each of said contact elements having a terminal portion extending along one of the end walls of the housing to a point adjacent one of the wire-receiving openings in the bottom of the housing, a block of insulating material fitted within and extending between the end walls of the housing, said block having a bottom and end walls engaging with and holding the terminal portion of the contacts against the end walls of the housing, said block having slotted recesses in the end walls and bottom thereof, each of said recesses having an opening opposite the terminal portion of one of the contact elements and an opening extending over one of the wire-receiving openings in the bottom of the housing, and a resilient wire-engaging member located in each of said recesses, said wire-engaging members having movable ends overlying the wirereceiving openings in the bottom of the housing in opposing relation to the terminal portions of the contacts and being anchored to the block at their other ends.

2. In an electrical wall switch, the combination which comprises a hollow housing, said housing having a bottom and upstanding side and end walls; a first contact element mounted in the housing, said contact element including. a contact portion and a terminal portion, said terminal portion extending along one of the end walls of the housing and toward the bottom thereof; a second Contact element mounted in the housing, said second contact element including a terminal portion extending along the opposite end wall of the housing and toward the bottom thereof, a spring arm carried by said second contact element, said spring arm extending lengthwise across the housing and having a free end positioned in opposing relation to the contact portion of the first contact element, said free end of the spring arm being normally biased away from the contact portion of the first contact element and being movable into engagement therewith; and a block of insulating material fitted within the housing beneath the spring arm of the second contact element, said block having end walls positioned in opposing relation to the end walls of the housing, said end walls of the insulating block engaging with and holding the terminal portions of the contact elements in fixed positions against the end walls of the housing.

3. In an electrical wall switch, the combination as defined in claim 2 wherein the end walls of the housing have contact-receiving grooves formed therein and the terminal portions of the contact elements are located in said grooves.

4. In an electrical wall switch, the combination as defined in claim 2 wherein the bottom of the housing contains wire-receiving openings, said openings being aligned with the inner surfaces of the end walls of the housing and communicating with the terminal portions of the contact elements mounted in the housing and the insulating block has slotted recesses formed therein, each of said recesses communicating with the terminal portion of one of the contact elements and extending over the wirereceiving opening associated therewith and which includes a resilient wire-engaging member located in each of said recesses, each of said wire-engaging members having a movable end extending over one of the wire-receiving openings in the bottom of the housing into opposing relation to the terminal portion of the contact element associated therewith and being anchored at its other end to the insulating block.

5. ln an electrical wall switch, the combination as defined in claim 4, wherein the wire-engaging members are L-shaped, with one leg of the L extending along the bottom of the housing and the insulating block has a recess formed therein into which the other leg of the L extends.

6. In an electrical wall switch, the combination as defined in claim 2 which includes a third contact element, said third contact element having a terminal portion extending along the first-mentioned end wall of the housing and toward the bottom thereof in spaced relation to the terminal portion of the first contact element between the opposing end walls of the housing and the insulating block and an offset contact-carrying portion carried by said third contact element, said offset portion extending transversely across the housing to a point above and spaced from the contact-carrying portion of the first contact element and contacting with the free end of the spring arm carried by the second contact element in one position thereof.

7. In an electrical wall switch, the combination as defined in claim 2 which includes an operating lever pivotally mounted in the housing above the block of insulating material, said lever being movable between two extreme positions, a member carried by said lever and engaging with the spring arm carried by the second contact element at a point intermediate its ends, said member being shaped to move the free end of the spring arm into engagement with the contact-carrying portion of the first contact element upon movement of the lever in one direction and a fiat spring mounted on top of the insulating block and acting on the lever, said spring having one end anchored to the insulating block and the other end free, said free end having cam surfaces formed thereof, said cam surfaces urging the lever toward one of its extreme positions upon movement of the lever away from its other extreme position.

8. In an electrical wall switch, the combination as defined in claim 7 which includes a pad of resilient material mounted on top of the block of insulating material, said pad engaging with the operating lever at each of the extreme positions thereof.

9. In an electrical wiring device, the combination which comprises a hollow housing of insulating material, said housing having a bottom with side and end walls extending upwardly therefrom, the bottom of the housing having wire-receiving openings extending therethrough at spaced points adjacent inner surfaces of the end walls, a pair of contact elements mounted in the housing, each of said contact elements having a terminal portion extending along the inner surface of one of the end walls of the housing to a point adjacent one of the wire-receiving openings in the bottom thereof, a block of insulating material slidably fitted within the housing and resting on the bottom thereof, saidV block having ends which oppose the terminal portions of the contact elements extending along the ends of the housing and having recesses formed therein which communicate, respectively, with the terminal portion of one of the contact elements and the wirereceiving openings in the bottom of the housing adjacent thereto, and a resilient wire-engaging member located in each of the recesses in said block, each of the wire-engaging members having an end anchored in the block and a free end extending over one of the wire-receiving openings in the bottom of the housing in opposing relation to the terminal portion of Ythe contact element adjacent said opening, said free end of the wire-engaging member being movable in an upward direction upon introduction of a wire into said opening.

10. In an electrical wiring device, the combination as defined in claim 9 which includes an operating lever pivotally mounted in theghousing above the block of insulating material, said lever being movable between two limiting positions, and a U-shaped member of resilient material mounted on top of the block of insulating material, said U-shaped member having a lower leg resting on top of the block of insulating material and an upper leg extending across the top of the block in spaced relation thereto, said upper leg engaging with the operating lever and urging said lever toward the respective limiting positions thereof.

1l. In an electrical wiring device, the combination as defined in claim l0 which includes a pad of resilient material carried on top of the blocky of insulating material and engaging with the operating lever before the lever reaches either of its limiting positions.

l2. In an electrical wiring device, the combination as defined in claim l0 wherein the U-shaped member is formed of fiat stock and the lower leg thereof is located in a recess in the top of the block of insulating material.

13. In an electrical wiring device, the combination as defined in claim 9 wherein one of the contact elements has ya portion resting on top of the block of insulating material and a portion extending beneath the block.

14. In an electrical wiring device, the combination as defined in claim 9 wherein one of the contact elements has a portion resting on top of the block of insulating material and a portion extending beneath the block and the other of said contact elements includes a movable arm extending across the top of the block of insulating material, said arm having a free end located above the portion of the other contact element resting on top of the block and being movable into contact therewith.

l5. In an electric wall switch, the combination of a hollow housing of insulating material, said housing having a bottom with side and end walls extending upwardly therefrom, a plurality of contact elements mounted Within the housing, each of said contact elements having a terminal portion extending along an inner surface of one of the end walls of the housing, a block of insulating material slidably fitted within the housing and resting on the bottom thereof, said block engaging With and holding the terminal portions of the respective contact elements in fixed positions relative to each other within the housing,

spedire an operating lever pivotaliy mounted in an opening in the housing above the block of insulating material and engaging with one of the contact elements, said lever being movable between two limiting positions and spring means carried on the block of insulating material and engaging with the operating lever, said spring means urging the operating lever toward one of the limiting positions thereof upon movement of the lever away from the other limiting position thereof.

16. in an electrical Wiring device which includes a housing of insulating material, said housing having `a bottom with end and side Walls extending upwardly therefrom, the bottom of the housing having spaced wire-receiving openings extending therethrough at positions adjacent inner surfaces of the end walls of the housing and a plurality of contact elementspmounted within the housing, each of said contact elements having a terminal portion extending along an inner surface of one of the end walls of the housing to a point opposite the wire-receiving openings in the bottom thereof, the improvement which comprises a block of insulating material slidably iitted with the housing and engaging with the terminal portions of the contact elements extending along the end walls thereof, said block having recesses formed therein, each of said recesses having an opening facing the terminal portion of one of the contact elements and the wire-receiving opening adjacent thereto, and a Wire-engaging member of resilient material located in each of said recesses, each of said wire-engaging members being anchored at one end in the block and having a movable end extending over one of the wire-receiving openings in the bottom of the housing and into opposing relation to the terminal portion of the contact element adjacent thereto.

17. In an electric Wall switch of the type which includes a hollow housing of insulating material having an opening at the top thereof and a bottom with side `and end Walls extending upwardly therefrom, a` cover having a slotted opening therein and extending over the top of the housing, an operating lever pivotally mounted in the housing with a portion thereof extending through the slotted opening in the cover and a pair of contact elements mounted within the housing7 the respective contact elements having terminal portions extending along opposite end Walls of the housing, the improvement which comprises a blockl of insulating material slidably fitted within the housing, said block having a top spaced below the cover and having ends opposing the end Walls of the housing, the ends of the block engaging and holding the terminal portions of the respective contact elements in ixed positions relative to each other and a U-shaped member of resilient material carried on top of the block and engaging with the operating lever, said U-shaped member urging the lever toward onel of two limiting positions of the lever upon movement of the lever past a central position.

References Cited in the file of this patent UNITED STATES PATENTS 1,401,652 Scully Dec. 27, 1921 1,645,387 Kinney Oct. 11, 1927 1,796,854 Millermaster Mar. 17, 1931 1,858,197 Wermine May 10, 1932 2,439,767 Wermine Apr. 13, 1948 2,841,673 Bernander July 1, 1958 2,848,574 Hutt et al. Aug. 19, 1958 

